Montenegro hopes to get an invitation to join NATO in December. Slovenia supports that since Montenegro has fulfilled all membership conditions, Cerar said.

As for EU membership, the Slovenian prime minister said the refugee crisis was putting the very existence of the EU at risk but should not affect the enlargement process.

The process of EU enlargement to the entire Western Balkans should continue with "unreduced speed," he said.

Đukanović said the country's EU and NATO aspirations would not be hampered by opposition protests, which have been escalating in Podgorica.

According to Đukanović, the protests are not directed at the government only, they are designed to prevent the "continuation of the European path" and reverse Montenegro's independence.